The NYT makes money from paid subscriptions. Anything that increases the virality of their subscriber acquisition is going to make back a whole bunch of money. There are lots of people that subscribe to the NYT principally for the games, which Wordle fits into nicely.
This deal makes perfect sense for NYT. I don't see it making sense for a lot of other companies (they don't already have an engine that you can stick games into and get subscriber dollars out of, and building that engine will swamp the cost of Wordle itself), but here, sure.
Hasbro would have been another one: stick it next to the sales page for Scrabble, pretty strong audience overlap I would think, and they have an instant winner due to the reduced marketing costs.
NYT has been charging separately and extra for access to their word games online for years. 'tptacek's explanation isn't wrong, it just undersells it by a lot - word games have been an NYT premium sub business since before their news digital sub business took off.
This deal makes perfect sense for NYT. I don't see it making sense for a lot of other companies (they don't already have an engine that you can stick games into and get subscriber dollars out of, and building that engine will swamp the cost of Wordle itself), but here, sure.